Figure 13-14.ASTM hydrometer.Figure 13-15.Dispersion cup and stirrer.will need 30 to 50 grams of air-dry material. When theflocculating (adhering to each other in clusters) shouldsample is mostly sand, you will need approximately 75be used. After it has soaked for approximately 16 hours,to 100 grams.the soil-water slurry is transferred to the dispersion cupFirst, place the sample in an evaporating dish. Then(fig. 13-15) and is mixed for 1 to 10 minutes dependingpour a solution of water (distilled or demineralized) andon the plasticity of the soil.a dispersing agent, such as sodium hexametaphosphate,over the sample to make a soil-water slurry. OnlyNext, you transfer the soil-water suspension to aenough water to submerge the sample completely and1,000-milliliter (mL) sedimentation cylinder and addenough dispersing agent to keep the soil particles fromdistilled or demineralized water to fill the cylinder to the13-17